Carlsberg has also launched a range it calls Crafted in a bid to capture the more discerning beer drinker.

AB InBev did not disclose how much it paid to get its hands on Camden Brewing Company.

But Camden’s own crowdfunding website suggests it was worth around £50m at the time of a fundraising exercise which closed in July.

A letter to shareholders about the latest deal revealed they were being offered between £1.0861 and £1.2526 per share, depending on whether they accept an option with a variable element based on sales growth. Reports said this was a return on investment of just under 70%, implying that AB InBev paid around £85m.

The founder of Camden Town Brewery, Jasper Cuppaidge, told the Guardian that investors should be “ecstatic” that the shares had been bought at a premium.

Cuppaidge, his family and three best friends own 95% of the company’s equity, suggesting that they have shared a combined payout of more than £80m.

The company’s latest accounts, for the year to the end of 2014, show a pre-tax profit of £319,000 on revenues of more than £9.5m.

Cuppaidge said the businesses now need a major investor to increase sales by funding the construction of a second brewery that will create 30 jobs.

He insisted that being bought by a large brewer would not force the company into brewing a more generic version of its brands.

“AB InBev are investing to build a new brewery to our exact standards, so I can continue to make great beer. They’re not making a beer for us.

“To stay at the forefront of this movement and secure our future success, we have to build a bigger brewery, employ more people and gain access to an international distribution network,” he said.

“We can’t do this on our own.”

He compared the company to smoothie maker Innocent, whose founders also decided to sell up after a blockbuster offer.

“You only have to look at brands such as Innocent ... They’ve gone from strength to strength by joining up with Coca-Cola,” he said.

But a question and answer session in which Cuppaidge took charge of the company’s Twitter account invited some less than enthusiastic comments.

Cuppaidge founded Camden Town Brewery in 2010 with just three staff. He has since built it into a well-known staple of London pubs, selling 12 million pints in 2015 from more than 1000 pubs, bars and restaurants.

Iain Newell, European director of craft beers at AB InBev, said: “We have a passion for great beer.

“Camden Town is a creative business with a great range of brands that will complement our existing portfolio.”

Mark Benner, managing director of the Society of Independent Brewers (Siba) said: “As craft beer continues to grow in popularity and steal market share we are likely to see more global brewers looking to take over craft breweries, something which makes membership to Siba even more important for breweries looking to differentiate themselves, as consumers look to seek out truly independent craft brewed beers.”

• This article was amended on 21 December 2015 because Guinness is owned by Diageo, not SAB Miller as an earlier version said.